Preheat the oven to 350 degrees F (175 degrees C). Line 12 muffin cups with paper liners.

Mix almond meal, coconut, sweetener, and baking powder together in a bowl.

Pour in eggs, banana, butter, and water to flour mixture. Blend using a hand mixer to combine thoroughly. Spoon batter into the prepared muffin cups, filling each 3/4 full.

Bake in the preheated oven until a toothpick inserted into the center of a muffin comes out clean, and tops are golden brown, about 15 minutes.